The present invention relates to a synthetic polymeric filament and to the preparation thereof.
The synthetic polymer is a polyamide that is known as nylon-6. Nylon-6 is chemically variously described as polymerized 6-amino caproic acid, polycaproamide or polyepsiloncaprolactam. In fiber form nylon-6 is known as Perlon L or Perlon.
As is known, both nylon-6 and nylon-66 (originally produced) are polyamides that are widely used for the production of fabrics for clothing. Nylon-66 is chemically polyhexamethylene adipamide. However, applicant has determined that nylon-66 has a crystallization speed that cannot be influenced by lowering temperature in order to meet the objective of the present invention. Accordingly, nylon-66 is excluded.
Nylon polyamides are commercially available in powder form for molding purposes.
The nylon-6 filament of the present invention differs from the conventional nylon-6 filament in that it allows fabric made therefrom to become pervious to ultraviolet rays from light sources such as sunlight.
Fabrics, thus highly permeable to ultraviolet rays, while suitable for making clothing in general, are particularly desirably suitable for making bathing costumes and beach clothes. Notwithstanding the danger of erythema, there is present day scientific evidence that the rays of sunlight do impart benefits to the human body. Accordingly, these benefits to the human body are denied by conventional outdoor vacation wear.
Attempts have been made in the past to achieve greater permeability of ultraviolet rays when making sportswear, as for bathing, for example, as follows.
German Pat. No. 535,817 (1931) employs a fiber mixture of glass fiber, cellulose, cellulose derivatives, products, synthetic glyptal, polyvinyl or polyacrylic acid and urea products.
German Pat. No. 826,581 (1949) used artificial acetate silk.
German Pat. No. 1,209,072 uses square-section threads of PVC (polyvinylchloride).
In contrast to the aforesaid prior art attempts to achieve a filament that permits the passage of ultraviolet rays, applicant uses an entirely different material, namely, nylon-6. Nylon-6, as well as various other known nylon type polyamides have been heretofore treated to avoid the harmful effects of light and heat as in the discoloration of the filaments, yarns or fabrics made therefrom, and to improve physical properties by providing non-circular cross-sections, for example. This is specifically exemplified in the following prior art U.S. Pat. Nos.:
Kimura et al. -- 3,729,449 PA0 Anton -- 3,377,314 PA0 Opfell -- 3,558,420 PA0 Stamatoff -- 2,630,421 PA0 Stamatoff -- 2,705,227 PA0 Strachan -- 3,156,607 PA0 Ellingsen -- 3,109,768
This patent relates to novel polyamide fibers or filaments which are circular or noncircular in cross section such as Y-shaped, T-shaped or H-shaped, obtained when spun through like shaped orifices. The patent mentions the inclusion of second components described merely as modifiers, stabilizers, coloring agents, pigments and other polymers. Antioxidants and conventional ultraviolet-ray absorbers are also mentioned. During polymerization there is added a mixture of copper acetate and potassium iodide to affect color tone and intrinsic viscosity. This patent does employ nylon-6, but not alone but rather in the preparation of a composite filament in combination with certain homopolymers of terephthalamides.
This patent, like the Kimura et al. patent, includes a mixture of copper acetate and potassium iodide in the polymerization preparation of polyamide filaments which may be of lobed or odd cross section. The resulting yarn is resistant to loss of strength when exposed to ultraviolet light. Known delusterants such as titanium dioxide, barium sulfate and aluminum trioxide may be added.
This patent relates to the production of hollow filaments of synthetic polymers including polyamides and employing individual orifices of various cross sectional shape. The filaments may have additive ingredients including delusterants such as titanium dioxide, calcium acetate and other opaque compounds, and a variety of heat and light stabilizers.
This patent relates to the stabilization of polyamides and particularly against discoloration due to prolonged exposure to heat and light. Along with a benzimidazole stabilizer plus phosphorous compound used in the polyamide formation there may be included in combination therewith alkali metal halides as potassium and sodium bromides. The stabilizer composition suppresses color formation and embrittlement.
Like the earlier Stamatoff patent, this patent relates to the stabilization of polyamides, but with a combination of a copper compound and an inorganic halide such as sodium or potassium bromide, but preferably also in combination with a phosphorous. This stabilizing mixture is added during the condensation reaction with a polyamide salt to provide "fairly good color stability," column 6, lines 80-82.
This patent discloses lobed filaments of polyamides containing titanium dioxide as a delusterant, to avoid the formation of picks and snags.
This patent discloses filaments of synthetic polymers, including polyamides, having a pentagonal cross-sectional configuration for the purpose of reflecting a substantial part of incident light. Titanium dioxide may be added to reduce sheen.